Great feature by Dave Girard for Ars Technica, “How QuarkXPress Became a Mere Afterthought in Publishing”:

Quark’s demise is truly the stuff of legend. In fact, the story
reads like the fall of any empire: failed battles, growing
discontent among the overtaxed masses, hungry and energized
foes, hubris, greed, and… uh, CMYK PDFs. What did QuarkXPress
do — or fail to do — that saw its complete dominance of
desktop publishing wither in less than a decade? In short, it
didn’t listen.

One thing that is often overstated is the notion that designers always despised QuarkXPress. Not so. The company was always problematic — tech support, software updates, everything was always a pain in the ass with them. And as Girard documents, they were arrogant, and felt as though they didn’t need to listen to their users. But the app was simply outstanding up through the 3.x releases. (I still remember my favorite release, which I used for years and years: 3.32r5.) QuarkXPress was fast and powerful, and once you understood the Quark way of doing the basics, it was easy to figure out the Quark way of accomplishing advanced tasks.

But the app and the company were easily conflated — everyone called them both “Quark”, and the company never really had any other app that mattered. As the years passed, disdain for the company turned into disdain for all things Quark. The biggest thing I wanted in QuarkXPress was better advanced typography — and that’s exactly what InDesign offered, right from the start. Then, a year or so later, Mac OS X shipped, and InDesign was native and QuarkXPress wasn’t. To top it off, none of the stuff in QuarkXPress 4 actually seemed like an improvement over 3.32r5. Game over.